I helped the ghouls because the tenpenny guys were a bunch of high society fags. But if the game was not so simplified (e.g. if the tenpenny people had do to "something" for their money and not magically "recieve" it from the game engine) I would help the humans.
Does the game give out hints what would happen if you let the ghouls in? Because some of the reports about that seemed like the player was surprised it happened. Does high perception help you notice something in the conservations or so?